Funds are requested for upgrading the WH-400 system at the UAB NMR Facility to provide state-of-the-art capabilities for researchers requiring high-resolution NMR spectroscopy at 400 MHz. Requested equipment includes an AVANCE DRX-400 console with orthogonal shim system, inverse probe with pulsed gradient capability, and low temperature control accessories. This upgrade modernizes the existing spectrometer system and permits its continued use for NMR investigations of small to medium-sized molecules. Because of its improved sensitivity, it allows observation of samples with limited solubility, and permits more efficient use of the system by allowing more experiments to be conducted. The pulsed field gradient capability also results in significant savings in time. The upgrade permits a wide variety of state-of-the-art 2D-NMR measurements. Projects which will utilize this upgraded system range from small organic compounds to peptides and glycopeptides, as well as animal cell and tissue suspensions.